1. Field of the Invention
The present invention generally relates to a retention module for retaining a heat sink to a package assembly. More particularly, the present invention relates to a package assembly retention module that is coupled directly to a socket.
2. Discussion of the Related Art
A heat sink is usually placed in contact with an electronic device, such as a Central Processing Unit (CPU), for removing heat therefrom. For higher-power devices, an integrated heat spreader (IHS) lid is generally placed between the heat sink and the electronic device to facilitate cooling the device. The electronic device is often mounted on a socket that couples to the motherboard. Various retention modules have been used for maintaining intimate contact between the heat sink and the IHS lid, or the bare package.
As shown in FIG. 5, a typical retention module is attached to the motherboard 150, often by passing the retention module through a motherboard hole 520 that is drilled into the motherboard 150 outside the perimeter of the socket 130 that couples to the motherboard 150. Drilling motherboard holes 520 takes up valuable space on the motherboard 150, approximately 25-50% more area than the socket 130 alone, thereby increasing the price of the motherboard 150. Furthermore, the area occupied by the motherboard holes 520 is close to a package 230, a space highly desirable to design engineers to place capacitors, voltage regulators, and other electrical components to optimize performance of the package 230. Holes are generally drilled into the heat sink 210 as well, so that the retention module may also pass through the heat sink 210. The heat sink 210 must extend outside the perimeter of the socket 130 that couples to the motherboard 150 to provide sufficient space for the retention module to pass through. Fasteners 530, such as clamps, screws, or nuts, are then coupled to the ends of the retention module to ensure a secure contact between the heat sink 210 and the IHS lid 220 or the package 230. A tool is required to apply the fasteners 530, which makes the assembly procedure more complicated.
Furthermore, having separate retention modules may give rise to inventory issues and increase both the cost of the package system and the number of piece parts. Although typical retention modules may be required to support the large heat sinks generally required in servers, the use of such retention modules may often be unnecessary and add cost in lower-power systems.
Thus, a retention module that requires neither additional motherboard space nor modifications to the motherboard is required.